Art theft is a booming business. According to the FBI, it is the third most lucrative international criminal operation after the illegal drugs and weapons trade. It is estimated to be worth approximately £3bn a year and this figure will continue to increase as the art market soars.

Movies like The Thomas Crown Affair have glamorized the theft of art, painting (excuse the pun) these criminals as harmless sophisticates who enjoy the thrill of outwitting authorities for fun. The reality is seedy and violent, often ending with the destruction or disappearance of irreplaceable pieces of history.

According to the Art Loss Register, a London-based organization that keeps a record of stolen art work, there are more than 7,500 works missing, including 572 Picassos, making Picasso the most sought after name by criminals. Other names in the top 10 include Miro, Dali, Warhol and Matisse.

Many works by these artists are world famous and easily recognizable, so how do thieves offload these works without arousing suspicion?

According to Julian Radcliffe of the Art Loss Register, there are a number of options. Thieves may patiently hold on to the painting for a decade or more in the hope that it will be forgotten about, willing to get their payoff years later. Or the art may move through an underground network, gradually increasing in value, before being slipped back onto the legitimate market. If it stays in the underworld, it can be used as collateral for international drug deals or other criminal activity as it is easier to slip past unknowing customs officials than money. In this scenario, it can pass through the hands of numerous criminals before being sold to an unwitting legitimate collector or dealer.

Norman Rockwell’s oil, “Russian Schoolroom”, was stolen from a Missouri gallery in 1973. In 2004, The FBI's Art Crime Team found out that the piece had been for sale at a New York Rockwell exhibition 15 years earlier and posted a picture and description of the painting on its art recovery web site. It turned out be in the collection of non other than Steven Spielberg. Spielberg had purchased it from a legitimate dealer in1989 for $200,000. Apparently the painting was auctioned in New Orleans in 1988, but it has yet to be determined who took the painting or its whereabouts from 1973 to 1988. Spielberg has maintained possession of the art work until courts can determine the rightful owner.

The other option is for thieves to try and ransom the art back to the museum or even the insurance company, who would rather get art back at a fraction of its original price than pay the owner its insured value.

But it could be years - or never - before the thief sees even a small payoff. "Our database makes it a lot more difficult to put works back on the market after a long time because we never take a work off the list," Mr Radcliffe said. "Seven works stolen in the USA in 1978, including a Cézanne, were all recovered by 2006. If used as collateral on drug deals, however, only a fraction of their true value is realized. Ransoms are rarely successful because there needs to be a pick-up and with intelligence nowadays the police often catch the thieves."

"Only 15 to 30 percent of high value paintings are recovered," Mr Radcliffe said. Most stolen art works are the more untraceable antiques and minor paintings stolen from stately homes, of which only 1 percent or so are recovered.

There have been numerous high profile art heists recently, including the theft of four paintings by Cézanne, Degas, Van Gogh and Monet, worth £82m, from the Emil Buehrle museum in Zurich. Only three days before that, two Picasso’s were stolen from an exhibition in Pfaeffikon, Switzerland.

These people are among the worst kind of criminal – denying the public their right to enjoy art that is a historic legacy that belongs to all of us.